• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2004년도 Annual Meeting of the Korean Society ofApplied Pharmacology
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• pp.18-34
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• 2004

This paper will review data obtained primarily from our preclinical investigations that show that exposure to stress has a significant impact on drug taking. Stress increases reward associated with psychomotor stimulants, possibly through a process similar to sensitization, and a growing clinical literature indicates that there is also a link between substance abuse and stress in human addicts. One explanation for the high concordance between stress-related disorders and drug addiction is the self-medication hypothesis, which suggests that a dually-diagnosed person often uses the abused substance to cope with tension associated with life stressors or to relieve symptoms of anxiety and depression resulting from a traumatic event. However, another characteristic of drug self-administration is that drug delivery and its subsequent effects on the HPA axis are under the direct control of the individual. This controlled activation of the HPA axis may result in the production of an internal state of arousal or stimulation that is actually sought by the individual (i.e., the sensation-seeking hypothesis). During abstinence, however, exposure to stressors or drug-associated cues can stimulate the HP A axis to remind the individual about the effects of the abused substance, thus producing craving and promoting relapse. Stress reduction, either alone or in combination with pharmacotherapies targeting the HPA axis may prove beneficial in reducing cravings and promoting abstinence in individuals seeking treatment for addiction. Of primary importance is to reduce the impact of cocaine-associated environmental stimuli on the HPA axis so that they no longer function as triggers for relapse.

• IMMUNE NETWORK
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• 제6권1호
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• pp.6-12
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• 2006

Background: The Hypothalamo-Pituitary-Adrenal (HPA) axis is an important regulator for the body's stress response. As a primary stress responsive system, HPA-axis secretes various neurotransmitters, hormones, and cytokines, which regulates the immune system. Natural killer (NK) cell which is plays an important role in the innate immune response, is specially decreased their numbers and loose cytolytic activity in response to stress. However, the effect of HPA-axis secreted proteins on NK cell activity has not been defined. Herein, we studied the effect of adrenal secreted adiponectin on NK cell cytotoxicity. Adiponectin which is well-known metabolic control protein, plays important roles in various diseases, including hypertension, cardiovascular diseases, inflammatory disorders, and cancer. Methods: Signal sequence trap was used to find stress novel secretory protein from HP A-axis. Selected adiponectin was treated mouse mature primary NK cells and then examined the effect of adiponectin to NK cell cytotoxicity and cytokine expression level. Results: We found that adiponectin which is secreted from adrenal gland, suppress IL-2 induced NK cell cytotoxicity. And also investigated cytolytic cytokines are suppressed by adiponectin. Conclusion: These data suggest that adiponectin inhibites NK cell cytotoxicity via suppression of cytotoxicity related target gene.

• Perspectives in Nursing Science
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• 제2권1호
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• pp.61-75
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• 2005

Physical and psychological events can produce stress response in various degrees. Stress affects many aspects of physiology including both brain and peripheral elements which is represented as hypothalamus-pituitary-adrenal axis. Brain elements consist of corticotropin-releasing hormone(CRH), locus ceruleus(LC)-norepinephrine(NE)/autonomic system. Peripheral elements include pituitary-adrenal axis and the autonomic nervous system, which coordinate the stress response. Current trend of the stress researches is emphasizing the mechanisms of the stress response which is adaptive or become maladaptive. This review introduces 1) the concepts of stress, 2) physiological and behavioral aspects of stress responses, 3) the consequences of stress response, 4) the measurements of stress and 5) stress management for those interested in stress research.

• 한국정밀공학회지
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• 제22권5호
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• pp.103-112
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• 2005

This paper presents one-axis high precision scanning system and illustrates the design of modified $X-Y-{\theta}$ stage as a tracker using VCM and commercialized air bearings for it. The scanning system for 100nm resolution is composed of the 3-axis stage and one axis long stroke linear motor stage as a follower. In this study a previous proposed and presented structure of VCM for the fine stage is modified. The tracker has 3 DOF($X-Y-{\theta}$ motions by four VCM actuators which are located on the same plane. So 4 actuating forces are suggested and designed to create least pitch and roll motions. This article will show about the design especially about optimal design. The design focus of this fine stage is to have high acceleration to accomplish high throughput. The optimal design of maximizing acceleration is performed in restrained size. The most sensitive constraint of this optimal design is heat dissipation of coil. There are 5 design variables. Because the relationship between design variables and system parameters are quite complicated, it is very difficult to set design variables manually. Due to it, computer based optimal design procedure using MATLAB is used. Then, this paper also describes the procedures of selecting design variables for the optimal design and a mathematical formulation of the optimization problem. Based on the solution of the optimization problem, the final design of the stage is also presented. The results can be verified by MAXWELL. The designed stage has the acceleration of about 5 $m/s^{2}$ with 40kg total mass including wafer chuck and interferometer mirror. And the temperature of coil is increased $50^{\circ}C$. In addition, the tracker is controlled by high precision controller system with HP interferometer for it and linear scaler for the follower. At that time, the scanning system has high precision resolution about 5nm and scanning resolution about 40nm in 25mm/s constant speed

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.94-97
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• 2003

This study uses ZnO thin film as a piezoelectric material and Pt as bottom electrode for FBAR (film bulk acoustic resonator) device. ZnO thin film and Pt were deposited by RF-magnetron sputtering method. ZnO thin film and Pt were oriented to c-axis. Top electrode Al was deposited by thermal evaporation. The membrane was formed of bulk micromachining. The FBAR was evaluated by XRD, SEM and electrical characterization. The resonant frequency was measured by HP 8753C Network Analyzer. A fabricated FBAR device exhibited a resonant frequency of 700 MHz ~ 1.5 GHz. When bottom electrode and top electrode thickness were fixed, the resonant frequency was increased as decreasing ZnO thin film thickness.

• 대한전기학회논문지
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• 제34권3호
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• pp.107-114
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• 1985

This paper presents the iterative algorithm for obtaining the ME PSE(Maximum Entropy Power Spectral Estimation) of 2-dimensional signals. This problem involves a correction matching power spectral estimate that can be represented as the reciprocal of the spectral of 2-dimensional signals. This requires two matrix inversion every iterations. Thus, we compensate the matrix to be constantly positive definite with relaxational parameters. Using Row/Column decomposition Discrete Fourier Transform, we can decrease a calculation quantity. Using Lincoln data and white noise, this paper examines ME PSE algorithms. Finally, the results output at the graphic display device. The 2-dimensional data have the 3-dimensional axis components, and, this paper develops 3-dimensional graphic output algorithms using 2-dimensional DGL(Device Independent Graphic Library) which is prepared for HP-1000 F-series computer.

• 대한기계학회논문집
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• 제8권5호
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• pp.442-449
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• 1984

본 연구에서는 두 분류가 교우되어 배합이 이루어지는 유동역에서 3차원 방향 에 대하여 평균속도분포, 난류강도분포, 난류전단응력분포, 상관계수의 분포 및 난류 운동에너지와 운동량의 변화 등을 측정 분석하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.509-512
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• 2001

Aluminum nitride(AlN) thin films were deposited on silicon substrates using RF magnetron sputtering at various deposition conditions and investigated the characteristics. It was used XRD, AES, SEM, and HP-4145B semiconductor parameter analyzer to analysis deposited AlN thin films. The deposition conditions for the good c-axis orientation were 100 W of RF power, $200^{\circ}C$ of substrate temperature and 15 mTorr of working pressure. The leakage current density was less then $1.3{\times}10^{-7}A/cm^{2}$. And it was also investigated the etching properties of deposited AlN thin films for application.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.509-512
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• 2001

Aluminum nitride(AIN) thin films were deposited on silicon substrates using RF magnetron sputtering at various deposition conditions and investigated the characteristics. It was used XRD, AES, SEM, and HP-4145B semiconductor parameter analyzer to analysis deposited AIN thin films. The deposition conditions for the good c-axis orientation were 100 W of RF power, 200$^{\circ}C$ of substrate temperature and 15 mTorr of working Pressure. The leakage current density was less then 1.3${\times}$10$\^$-7/ A/$\textrm{cm}^2$. And it was also investigated the etching properties of deposited AIN thin films for application.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.111-118
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• 2015

Osteoprotegerin (OPG), receptor activator of NF-${\kappa}B$ ligand (RANKL)/receptor activator of NF-${\kappa}B$ (RANK) axis, and TNF-related apoptosis-inducing ligand (TRAIL) participate in vascular calcification process including atherosclerosis, but their contributions under high glucose (HG) and phosphate (HP) condition for a long-term period (more than 2 weeks) have not been fully determined. In this study, we evaluated the effects of HG and HP levels over 2 or 4 weeks on the progression of vascular calcification in rat vascular smooth muscle cells (VSMCs). Calcium deposition in VSMCs was increased in medium containing HG (30 mmol/L D-glucose) with ${\beta}$-glycerophosphate (${\beta}$-GP, 12 mmol/L) after 2 weeks and increased further after 4 weeks. OPG mRNA and protein expressions were unchanged in HG group with or without ${\beta}$-GP after 2 weeks. However, after 4 weeks, OPG mRNA and protein expressions were significantly lower in HG group with ${\beta}$-GP. No significant expression changes were observed in RANKL, RANK, or TRAIL during the experiment. After 4 weeks of treatment in HG group containing ${\beta}$-GP and rhBMP-7, an inhibitor of vascular calcification, OPG expressions were maintained. Furthermore, mRNA expression of alkaline phosphatase (ALP), a marker of vascular mineralization, was lower in the presence of rhBMP-7. These results suggest that low OPG levels after long term HG and phosphate stimulation might reduce the binding of OPG to RANKL and TRAIL, and these changes could increase osteo-inductive VSMC differentiation, especially vascular mineralization reflected by increased ALP activity during vascular calcification.